SINCODA 2 Pack RJ9 4P4C Male to 3.5mm Female Headset Phone MIC Audio Splitter Adapter Cable

Feature:
3.5mm audio female socket to RJ9 Modular Plug Adapter Cable for connecting your own Analog Headphone to chat on telephone.
This amazing adaptor converts the standard phone headset 3.5mm plug to an RJ9, RJ10, or RJ22 headset plug, allowing you to use your favorite 3.5mm headset with your office IP phone.

PC Headset Adapter for Cisco IP Phones

Why buy an expensive headset just for your office phone? Use the Headset Buddy Adapter and your existing computer headset with most Cisco VOIP office phones that have a headset jack.
A money saver for home businesses, call centers, sales people, or anyone who is on the phone all the time, and wants to use a lower cost or more comfortable PC headset.
Specs: This amazing adaptor converts the standard headset 3.5mm mic/audio plugs to a standard RJ9, RJ10, or RJ22 handset plug, allowing you to use your favorite computer/laptop headset with 

your Cisco IP phone. This adapter is designed for use with headsets that have two 3.5 mm. plugs; one for the microphone and one for the headphones/earpiece(s). The adapter outputs binaural 

sound for stereo headsets, meaning you will hear sound out of both ears. The adapter cable is approximately five inches long. 
Example Compatible Phones for PC Headset to Cisco IP Phone Adapter:

Cisco IP phone headset jack for models: 7931G, 7940, 7941G, 7942G, 7945G, 7960, 7961, 7961G, 7962G, 7965G, 7970, 7971, 7971G, 7975, 7975G, 7975G, 7965G, 7945G, 7962G, 7942G

Does not work with Polycom, Nortel, Aastra, and other phones, only Cisco and Ativa phones. Will not work with the handset jack or an RJ11 jack (wall jack).
Incompatible Cisco phones:
Cisco 7902, 7905, 7910, 7911, 7912, 7920, 7921, 7961.